How do you tell the difference between male and female penguins?

Other than waiting around to see which penguins lay eggs and which ones do not, it is quite difficult to tell male and female penguins apart, as if waiting to see if they lay eggs wouldn’t be difficult enough. In fact in most species of penguins it is so difficult to tell males from females that you can’t do it at all. The crested penguins are the exception, in that species the males are more robust and have larger bills. There are two species of crested penguins, the Fiordland crested and the Erect-crested penguins. The other fifteen species of penguins are dimorphic, which is to say they cannot be told apart by simply looking at them.

Another interesting method of telling the two apart (similar to seeing which ones lay eggs) is to note which penguins bring stones to other penguins. As part of the courting ritual a male penguin will bring small stones to a female in hopes of winning her over. Sound familiar? It might, we perform a similar ritual but we call the stones diamonds.

If you really must tell the difference I’m afraid you’ll have to simply wait and watch or perform a closer inspection than you wish to.

I assume the smaller King penguin is the female but in the case of penguins size dosen’t matter, after all the smaller one may simply be younger..